A personal, guided tour to the best scoops and stories every day in The Wall Street Journal, from Editor in Chief Gerard Baker.

Gerard Baker is away. Today’s 10-Point is by Deputy Editor in Chief Matt Murray. Follow him on Twitter @MurrayMatt.

An Evolving Threat

In the first indication Islamic State has obtained a banned chemical weapon, the militant group likely used mustard agent in an attack earlier this week on Kurdish forces in Iraq. The use of mustard...